A variety of magnetic tape cassettes have been developed which employ two rotatable hubs or spools with magnetic tape connected to both hubs and wound upon one or both hubs. Usually the cassette includes sections of a leader tape attached to each spool or hub, with the magnetic tape having its opposite ends spliced to the two leaders. Cassettes of this type have been developed for both audio and video magnetic tape. Magnetic tape cassettes of the audio type are generally shown in U.S. Pat. Nos. 3,423,038, 3,753,835, 3,797,770, 3,167,267, and 4,062,719. Video cassettes are more complicated than audio cassettes and generally have a door which is normally closed to conceal the magnetic tape and leader. When the video tape cassette is to be used, the door is opened so as to allow the tape to be transported past the Read and Write magnetic heads of a VCR (video tape cassette recorder) machine.
Two types of VCR machines have achieved substantial commercial success. One type, known as the VHS format machine, uses a cassette having a pivoted door along one side, first releasable door locking means at a first side of the cassette body for keeping the door locked, and second releasable hub locking means for preventing rotation of the cassette hubs. The second type of commercially successful VCR machine, known as the Betamax format machine, uses a cassette which is similar to the VHS cassette but differs in size, has its door locking means located at the second or opposite side of the cassette, and has a hub locking mechanism which is unlocked with the door.
Cassettes loaded with a selected amount of magnetic tape are generally manufactured in one of two ways. The first way involves starting with two hubs with a length of leader tape secured to and extending between the two hubs, severing the leader tape into two sections, splicing magnetic tape to the leader section connected to a first one of the two hubs, winding a selected length of magnetic tape onto that first hub, splicing the trailing end of the magnetic tape to the leader section connected to the second hub, and then inserting the two hubs into a cassette body. This type of loading is commonly called "hub loading". The second common method is to load magnetic tape directly into a C-Zero cassette. A "C-Zero cassette" is one which consists of a cassette body, two hubs rotatably mounted in the cassette body, and a length of leader tape connecting the two hubs. This type of cassette loading, commonly called "in-cassette loading", also involves cutting the leader tape to form two discrete leaders, splicing one end of a magnetic tape to the leader connected to a first cassette hub, winding magnetic tape onto the first hub, and splicing the trailing end of the magnetic tape to the second leader section. Where in-cassette loading is the practice, the procedure further involves the additional step of slowly winding the trailing end of the magnetic tape into the cassette after the second splice has been made, so that the magnetic tape and the trailing leader are fully pulled into the cassette.
Heretofore, in-cassette loading of video tape cassettes has been hampered by the fact that the VHS and Betamax cassettes (a) have leaders which are relatively short as well as having different lengths, and (b) are of different size and employ different locking mechanisms. The relatively short leaders and the fact that the splicing tape must be applied to the inner surface of the leader when making a splice have restricted the design of the means used to extract the leader from the cassette and the means which support the leader during the splicing and winding operations. A further complication in the design of in-cassette video tape loading machines is that manufacturers of video cassettes may require that the length of the leader at one or both ends of the magnetic tape be within certain prescribed limits. Also, because of the relatively high cost of video tape cassettes, manufacturers are quite concerned about the cosmetic appearance of the cassettes and are unwilling to utilize loading machines which may damage the exterior appearance of the cassette, provide uneven loading of magnetic tape, or damage the tape. As a result state of the art in-cassette video tape loading machines are capable of loading only one type of cassette and hence two different machines are required to be purchased for loading VHS and Betamax cassettes. Other limitations of state of the art in-cassette video tape loading machines are relatively low production rates and slow and complicated means for extracting the leader from a cassette and placing it in position to be cut and spliced to the magnetic tape which is to be loaded into the cassette. Another problem associated with prior art loading machines is that the various tape-handling components are spread apart from one another to an extent that causes the machines to be relatively large and slow. State of the art in-cassette loading machines also are relatively expensive.
Still other disadvantages, problems and limitations of existing in-cassette video tape loading machines are well known to persons skilled in the art. Such disadvantages, problems and limitations have influenced some manufacturers of video tape cassettes to utilize hub loading machines even though such machines involve more manual labor.